Merge bodhi.(none):/opt/local/work/mysql-5.0-runtime

into  bodhi.(none):/opt/local/work/mysql-5.1-runtime


mysql-test/r/trigger.result:
  Auto merged
mysql-test/t/query_cache.test:
  Auto merged
mysql-test/t/sp.test:
  Auto merged
mysql-test/t/trigger.test:
  Auto merged
sql/item.cc:
  Auto merged
sql/item.h:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/sp_head.h:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_db.cc:
  Auto merged
sql/sql_lex.cc:
  Auto merged
sql/sql_lex.h:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/sql_show.cc:
  Auto merged
sql/sql_trigger.h:
  Auto merged
sql/sql_view.cc:
  Auto merged
sql/table.cc:
  Auto merged
storage/myisam/ha_myisam.h:
  Auto merged
mysql-test/include/mix1.inc:
  Manual merge.
mysql-test/r/information_schema.result:
  Manual merge.
mysql-test/r/innodb_mysql.result:
  Manual merge.
mysql-test/r/query_cache.result:
  Manual merge.
mysql-test/r/sp.result:
  Manual merge.
mysql-test/t/information_schema.test:
  Manual merge.
sql/handler.h:
  Manual merge.
sql/sp.cc:
  Manual merge.
sql/sp_head.cc:
  Manual merge.
sql/sql_prepare.cc:
  Manual merge.
sql/sql_trigger.cc:
  Manual merge.
sql/sql_yacc.yy:
  Manual merge.
sql/table.h:
  Manual merge.
storage/myisam/ha_myisam.cc:
  Manual merge.

2 files changed, 82 insertions, 0 deletions

diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index 98f74247707..20f55545282 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -2075,3 +2075,78 @@ mysql_declare_plugin(myisam)
 }
 mysql_declare_plugin_end;
 
+
+#ifdef HAVE_QUERY_CACHE
+/**
+  @brief Register a named table with a call back function to the query cache.
+
+  @param thd The thread handle
+  @param table_key A pointer to the table name in the table cache
+  @param key_length The length of the table name
+  @param[out] engine_callback The pointer to the storage engine call back
+    function, currently 0
+  @param[out] engine_data Engine data will be set to 0.
+
+  @note Despite the name of this function, it is used to check each statement
+    before it is cached and not to register a table or callback function.
+
+  @see handler::register_query_cache_table
+
+  @return The error code. The engine_data and engine_callback will be set to 0.
+    @retval TRUE Success
+    @retval FALSE An error occured
+*/
+
+my_bool ha_myisam::register_query_cache_table(THD *thd, char *table_name,
+                                              uint table_name_len,
+                                              qc_engine_callback
+                                              *engine_callback,
+                                              ulonglong *engine_data)
+{
+  /*
+    No call back function is needed to determine if a cached statement
+    is valid or not.
+  */
+  *engine_callback= 0;
+
+  /*
+    No engine data is needed.
+  */
+  *engine_data= 0;
+
+  /*
+    If a concurrent INSERT has happened just before the currently processed
+    SELECT statement, the total size of the table is unknown.
+
+    To determine if the table size is known, the current thread's snap shot of
+    the table size with the actual table size are compared.
+
+    If the table size is unknown the SELECT statement can't be cached.
+  */
+  ulonglong actual_data_file_length;
+  ulonglong current_data_file_length;
+
+  /*
+    POSIX visibility rules specify that "2. Whatever memory values a
+    thread can see when it unlocks a mutex <...> can also be seen by any
+    thread that later locks the same mutex". In this particular case,
+    concurrent insert thread had modified the data_file_length in
+    MYISAM_SHARE before it has unlocked (or even locked)
+    structure_guard_mutex. So, here we're guaranteed to see at least that
+    value after we've locked the same mutex. We can see a later value
+    (modified by some other thread) though, but it's ok, as we only want
+    to know if the variable was changed, the actual new value doesn't matter
+  */
+  actual_data_file_length= file->s->state.state.data_file_length;
+  current_data_file_length= file->save_state.data_file_length;
+
+  if (current_data_file_length != actual_data_file_length)
+  {
+    /* Don't cache current statement. */
+    return FALSE;
+  }
+
+  /* It is ok to try to cache current statement. */
+  return TRUE;
+}
+#endif
diff --git a/storage/myisam/ha_myisam.h b/storage/myisam/ha_myisam.h
index 6cc9f4811b0..024675075c2 100644
--- a/storage/myisam/ha_myisam.h
+++ b/storage/myisam/ha_myisam.h
@@ -137,4 +137,11 @@ class ha_myisam: public handler
   int dump(THD* thd, int fd);
   int net_read_dump(NET* net);
 #endif
+#ifdef HAVE_QUERY_CACHE
+  my_bool register_query_cache_table(THD *thd, char *table_key,
+                                     uint key_length,
+                                     qc_engine_callback
+                                     *engine_callback,
+                                     ulonglong *engine_data);
+#endif
 };